Restore custom styled window controls

src/App.tsx

@@ -4,6 +4,8 @@ import {
   FileDown,
   FileInput,
   Languages,
+  Maximize2,
+  Minus,
   Plus,
   RefreshCcw,
   Settings,
@@ -271,14 +273,6 @@ function readTheme(): ThemeMode {
   return stored && themeLabels.includes(stored) ? stored : "system";
 }
 
-function getEffectiveTheme(themeMode: ThemeMode): "light" | "dark" {
-  if (themeMode !== "system") {
-    return themeMode;
-  }
-
-  return window.matchMedia("(prefers-color-scheme: dark)").matches ? "dark" : "light";
-}
-
 export default function App() {
   const [input, setInput] = useState(sampleEnv);
   const [loadedPath, setLoadedPath] = useState<string | null>(null);
@@ -294,16 +288,6 @@ export default function App() {
   useEffect(() => {
     document.documentElement.dataset.theme = themeMode;
     localStorage.setItem("envhelper-theme", themeMode);
-
-    const updateTitlebar = () => {
-      void window.envHelper?.setTitlebarTheme(getEffectiveTheme(themeMode));
-    };
-    const media = window.matchMedia("(prefers-color-scheme: dark)");
-
-    updateTitlebar();
-    media.addEventListener("change", updateTitlebar);
-
-    return () => media.removeEventListener("change", updateTitlebar);
   }, [themeMode]);
 
   useEffect(() => {
@@ -351,6 +335,23 @@ export default function App() {
           <div className="titlebarMark">EH</div>
           <span>EnvHelper</span>
         </div>
+        <div className="windowControls">
+          <button aria-label="Minimize" onClick={() => window.envHelper?.minimizeWindow()} title="Minimize" type="button">
+            <Minus size={15} />
+          </button>
+          <button aria-label="Maximize" onClick={() => window.envHelper?.toggleMaximizeWindow()} title="Maximize" type="button">
+            <Maximize2 size={14} />
+          </button>
+          <button
+            aria-label="Close"
+            className="closeButton"
+            onClick={() => window.envHelper?.closeWindow()}
+            title="Close"
+            type="button"
+          >
+            <X size={15} />
+          </button>
+        </div>
       </section>
 
       <header className="toolbar">